My vote is the same as Lowe Flieger.
As to Canada's requirements, I was just a shag pilot, and wouldn't feel qualified to argue with the Generals. However, I would note the following.
Complete engine failure on long oversea/night/remote area mission would be liable to result in death quite often. I can recall numerous sorties where we would have been unlikely to survive the parachute descent (surface windspeed), or died of hypothermia long before rescue reached us. I would thus be bloody unhappy about flying single-engine.
"Quantity has its own quality"
There is also a tendency to fight the last war. I would purchase Super Hornet before 2020, and get to work on UAVs right now. I strongly suspect they will be the major (but not sole) component of Air Forces by 2040. It also gives Canada, and every other smaller nation like Australia, The Netherlands, etc, a chance to get back into the aircraft building business.